Warning: Spoilers ahead for Doctor Who season 15, episode 2, "Lux."The villain in Doctor Who season 15, episode 2, "Lux," enters the fray in a very unorthodox way, and it connects the installment's titular character to the show's primary protagonist. Alan Cumming's Mr. Ring-a-Ding/Lux Imperator initially seems to be "just" an animated character that has come to life, but the reveal that he is a member of Doctor Who's Pantheon as the God of Light comes shortly after his introduction.